-- AP1.14: Plan-Snapshots (Plan-Revision) — Soll-Zustand getrennt von Ist

CREATE TABLE roadmap_plan_snapshots (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    tenant_id UUID NOT NULL REFERENCES tenants(id) ON DELETE CASCADE,
    initiative_id UUID NOT NULL REFERENCES initiatives(id) ON DELETE CASCADE,
    roadmap_id UUID NOT NULL REFERENCES roadmaps(id) ON DELETE CASCADE,
    revision_number INT NOT NULL,
    reason TEXT NOT NULL DEFAULT '',
    plan_payload JSONB NOT NULL,
    created_by_user_id UUID NULL REFERENCES users(id) ON DELETE SET NULL,
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    UNIQUE (tenant_id, initiative_id, revision_number)
);

CREATE INDEX idx_roadmap_plan_snapshots_initiative
    ON roadmap_plan_snapshots(tenant_id, initiative_id, created_at DESC);